from math import sqrt

class mymath():
    def add(self, x, y):
        return x+y
    def reduction(self, x, y):
        return x-y
    def take(self, x, y):
        return x*y
    def division(self, x, y):
        if y==0:
            return print('除数不能为0')
        else:
            return x/y
    def power(self, x, y):
        return x**y
    def prescrib(self, x):
        return sqrt(x)

c=mymath()
print(c.division(10,0))
print(c.prescrib(9))
print(c.power(8,9))


#自由课题
class wash():
    def one(self):
        c=[]
        a=input('这件衣服是否干净')
        if a == '干净':
            pass
        else:
            c.append(a)
        print('找好要洗的衣服')
        return len(c)
    def two(self):
        print('把衣服放入洗衣机')
    def three(self):
        print('倒入洗衣粉')
    def four(self):
        print('接入电源，点击开始')
g=wash()
print(g.one())
